Fire extinguisher



Sept. 18, 1934.

c.. A: THOMAS ET AL FIRE EXTINGUISHER Filed May 29, 1929 I ls closure;

Patented Sept. 18, 1934 FIRE EXTINGUISHEB Charles A. Thomas and Carroll A. Hochwalt,

Dayton, Dhio, assignors to The Fyr-Fyter Company, Dayton, Ohio, a corporation of Ohio Application May 29, 1929, Serial No. 366,947

20 Claims.

Thisinvention relatestofire extinguishers of the foam type and more particularly to charges for use insuch fire extinguishers. It among the objects ofthis invention to projfi gvide a charge for fire extinguishers of the, foam type -Which has unusual and superior fire-extinguishing properties and suflicient to meet the present requirements for such extinguishers.

Another object of this invention is,to provide ;a charge for fire extinguishers of the foam type whichis nonfreezing at extremely low temperatures and whichreacts with high efiiciency to generate an extinguishing foam at such low temperatures.

Still another object of the invention is to provide a superior method of extinguishing fire,

utilizing the above charge.

Other objects and advantages of this invention will be apparentfrom the following dis- In-the drawing, in which like characters of reference designate like parts throughout the several'viewsthereof,

Fig. 1 is a vertical sectional View of a form of foam extinguisher which functions very satisfactorily for receiving a charge prepared in accordance with this invention; 7

Fig. 2 is a horizontal sectional view taken on the plane of thelineZ-Z of Fig. 1; and

Fig, 31s a vertical sectional view of a modifiedform of extinguisher which will function satisfactorilyfor receiving a foam charge of this invention where, a sealed acid bottle is desirable.

Charges for foam extinguishers, as heretofore used, generally comprised an outer basic solution containing, a gas-generating material, ordinarily sodium bicarbonate, and .a foam stabilizer such as extract of licorice, and an inner solution of aluminum sulphate. When put into use, a chemical reaction takes place between the acid salt of aluminum and the gas-generating material which produces a gaseous pressure for expelling the fire-extinguisher fluid, and due, to the, presence of, the foam stabilizer, a. tenacious and last- ;ingfoam which isdischargedfrom'the extinguisher; the, aluminumhydroxide formed. dur

ing the reaction being said to provide a latticework, forthe foam.

Wehave discovered that the fire-extinguishing properties of a foam extinguishermay be mag terially increased above the heretofore-knownv extinguishing characteristics by the introduction of certain compounds into the foam-producing;

solutions, which compounds involve a certain group of elements, and which, we 'havefound to an element of group I of the periodic table of 3 elements. Particularly, those elements of group I which have the higher atomic weights and which are positioned below sodium in the arrangement of the periodic table, namely, potassium, rubidium and caesium, possess unusually efficacious fire-extinguishing qualities. In general, these elements, when combined with a rad ical, either organic or inorganic, present a group of substances which prove upon test to have peculiarly advantageous fire-extinguishing properties.

For example, wehave found that a compound composed of the element potassium, which is one of the elements of group I referred to, combined with an organic radical such as a lactate, will constitute an excellent material tof be added tothe basic, solution of V a foam charge. Other com}; pounds of. potassium, or of other elements of group I of the periodic table, may be substituted for the potassium lactate to give the desirable high fire-extinguishing properties to theextin guishing foam. Thus, other organic compounds of the elements referred to, suchas other members of the carboxylic acid class andits various subclasseswhich embrace for example the formates, acetates, stearates, oxalates and tartrates, possess these exceptional fire-extinguishing properties. Also, inorganic compounds of these ele ments such as the halogen compounds including. the chloride, bromide, iodide andfluoride, and especially the oxygenated compounds of the halogens such as the chlorate, the nitrates and the nitrites, 'all possess these high fire-extinguishing. properties to an unusual degree. While sodium. compounds are generally inferior to potassium, rubidium. and caesium as regards fire-extinguishing' effect, .we have discovered certain compounds of sodium, such as sodium acetate, sodium lactate and sodium nitrate, have special or unusual fireextinguishing qualities.

These compounds, such as potassium lactate, should be introduced into. the foam producing? solutionin sufficient. amount to provide a relatively high metal content, such asa high potassium content, to get the best extinguishing effects; The foam producedwhen such materials are present in substantial quantities to materially increase the fire-extinguishing properties of the foam, for example in excess of 10% by weight is generally a so-called wet foam, comprising adtenacious and lasting foam.

hering bubbles of gas which carry along suspended particles of liquid, and the liquid in these instances is of high fire-extinguishing effect due to the presence of such compounds having unusual extinguishing qualities. A superior extinguishing effect of the foam is obtained by the introduction into the generated foam of finely divided or dispersed drops of a rather concentrated solution of one of these alkali metal compounds having inherently exceptional fire-extinguishing properties. The superior results may be obtained from a combination of the smothering effect of the foam blanket and an extinguishing effect of the entrained particles of solution of these compounds carried along with the foam.

The use of these compounds, such as potassium lactate provides important advantages other than the superior fire-extinguishing effect. Potassium lactate, for example, materially depresses the freezing point of the solution, thus serving as a freezing temperature depressant. By using sufficient quantities of potassium lactate, which may approach the point of saturation, a solution is obtained which will withstand extremely low temperatures of the. order of 20 C. and below and still not affect the foam producing qualities of the solution. Moreover, the presence of potassium lactate in the solution provides for the generation of a good foam comparable, from the practical viewpoint, with the foam produced through the use of aluminum salts, which, as stated above, are adapted to form the latticework upon which the foam builds or is supported to provide a more Sodium lactate may be usedin place of potassium lactate, and give the advantages of 7 increased fire-extinguishing properties, the latticework effect to obtain a tenacious foam, and the lowering of the freezing point of the solution. We prefer to use potassium lactate as the fire-extinguishing properties of this compound are even superior to those of sodium lactate. Any suitable gas-generating material, such as a suitable carbonate, .and any suitable foam stabilizer, such as extract of licorice, may

be usedto provide this superior foam forming composition.

Any suitable gas-generating material which is not too strongly alkaline in water solution may be used in this composition. We have found that a strongly alkaline material, such as potassium carbonate, is not so satisfactory in a foam charge. While such a carbonate will produce the necessary carbon dioxide gas, the strong alkalinity of the solution tends to destroy the foam.. Carbonates which do not have this strong alkaline reaction are quite satisfactory. Very satisfactory results have been obtained with sodium bicarbonate. The alkali metal compound having inherently exceptional fire-extinguishing properties should also not be sufliciently alkaline. to

destroy the foam. An alkalinity materially less,

than that of potassium carbonate is not objectionable. The composition may be shipped to the user in the form of a powder and then dissolved in water to produce the basic solution of a foam charge, or the basic solution may be initially formed and shipped to the user.

In order to still further depress the freezing .point ofthis basic solution, any suitable freezing temperature depressant material, which is amounts serve to lower the freezing point of the basic solution containing a potassium salt, or

other salt or salts referred to having high fireextinguishing properties as well as freezing temperature depressant properties, to extremely low temperatures to render the basic solution nonfreezing in very cold climates. Ethylene glycol is free flowing or of sufficiently low viscosity at such extremely low temperatures to permit its use in this capacity. Alkali metal acetates are also exceptionally good freezing temperature depressants, and these materials serve in addition to increase'the fire-extinguishing properties of the solution. Thus we have found potassium acetate to be highly effective for this purpose, and when used in conjunction with potassium lactate in certain proportions, a solution is obtained which has a freezing point below -40 C., which is sufiiciently low to meet the requirements of Underwriters Laboratories to obtain a preferred rating.

As examples of basic solution charges prepared in accordance with our invention, the following may be mentioned. Where the charge need not withstand unusually severe winter temperatures, the following provides a very satisfactory solution:--

Percent by weight Potassium lactate 30 Sodium bicarbonate 8 Extract of licorice; 2 Water 60 Approximate freezing point 22 C.

Both potassium lactate and sodium lactate may be used in the basic charge as illustrated in the following example:-

of alkali metal acetates in this basic charge, the following examples utilizing potassium acetate in addition to potassium lactate are menti0ne'd:-

Percent by' weight Potassium lactate -36 Sodium bicarbonate 9 Potassium acetate i 9 Extract of licorice 2 Water 44 Approximate freezing point -35 C.

Percent by weight Potassium lactate 36 sodium bicarbonate 9 Potassium acetate 12 Extract of licorice 2 Water 41 Approxim te freezing point -42 C.

- The basic solution may be used with any acid liquid :orsolu'tion of any acid-salt which will react with the gas-generating material to produce the expelling gas. For example, an ordinary solution of aluminum sulphate may be :used as the acid liquid.

Referring to the drawing, 'thereis'disc'losed in Figs. 1 .and 1-2 .a preferred embodiment of portable fire-extinguishing apparatus, which isadapted :to "be used when :a relatively 'large 'volume of acid liquid iscrintained in the charge, such as when an aluminum sulphate solution is used. This extinguisher comprises .a sheetmetal container having a portion 11 with a flat face which serves 'as' 'a base on which the container may set when not :in 11158.. The :lower 'endo'f the container is closed :by ;a sheet metal bottom 12 which may :be fastened to the wall of the outer shell in any suitable .manner .such as by soldering. The top end is provided with a centrally arranged opening which {receives therein a cover casting 1'4 to which :this end 0f the shell '10 is soldered. The upper end :of the cover casting leis threaded to receive thereon a .cover member 15 carrying a suitable handle 16, which :as shownis in-the form-of 1a ring :to serve as a .base upon which the extinguisher ,is "adapted .to :r'est when inverted. Adjacent the upper end :of the "extinguisher and passing through'the wall of the extinguisher shell is a discharge :casting or fitting 20. This'casting is provided with 2an'enlarged shoulder .21 which is .soldered .to the :shell. The inner end of the casting is provided with a flaring member receiving ;a :screen 22, and "the otherend of the casting :is formed as :athreaded nipple 23. whichreceives the usual .flex'ible hosei24= carrying a discharge nozzle :25.

- -'-I-he cover casting leis provided with an interior annular shoulder upon .which fa vcagehead casting 31 rests. An inner "tube .of sheet metal forming an inner container ;32 ;is;-soldered to 'the cage head as "at :3-3. This inner :container is of sufficientcapacit y to hold thedesired quan- Iity'of acid liquid, such as the aluminum .'-s1ilphate solution. On the inner side of the .cage head 31v is an inwardly :andaupwardly extending annular flange 35 forming a :seat {for :a r-stopple 36, which stopple upon inversion iof'the -:extinguisher is adapted to -'fall away :fromtheseat to permit the mixing of the acid solution inithe inner container with the-basic solution held within the outer container.

As shown clearly Figs. :1 and 2, the cage head 31 is cut away :above :the "stopple seat :35 and-on the side opposite the discharge casting 120 to provide discharge, ports 38 :for the-discharge of the acidliquid into .the space within the :outer container. The wallet-the:cage head:-31is left blank .or imperforate .on the. side'adiacent the discharge casting 20. This construction insures against any escape of unreactedzacid through-the asfichlorosulphonic.acid,.orvother acid compound containing a sulphonic acid radical, is preferably substituted for the acid solution as above de-.

scribed. Such an acid withstands temperatures materially below 40 C. without freezing. When this acid 'is-used inconiunction with a non-freezing basic solution as above referred to, a foam extinguisher is provided in which the normally separated portions of the charge are non-freezing and furthermore will react with high efficien cy at extremely low temperatures. Such a foam charge will withstand temperatures of :the order of 40 C. .and lower, and the separate portions of the charge are chemically active with respect to each other to generate an extinguishing foam with high efficiency at such low temperatures; Only a relatively small volume of chlorosulphonic acid is required :to provide a sufficient amount of the acid to generate the desired quantity of ex pelling gas. "For example, about 2 /2 fluid ounces of .chlorosulphonic acid is sufficientto react with and expel a gallon and a half of the basic solu tionin the form of a stabilized foam. 1

Referring to Fig. '3 of the drawing, apreferred form of portableextinguishing apparatus is dis .closed,'whichis adaptedto be used as a'foam extinguisherwhen an acid such as chlorosulphon'ic acidlis employed, where a sealed acid bottle is desirable. The outer shell, discharge casting and cover-are constructed similarlyto that previously described. In this construction, an annular ring member 40 is provided which rests upon a shoulder 30 in :the cover casting 14'. The member '40 is provided with downwardly and inwardly extending .arms 42 connected at their lower ends with a cylindrical member 43, preferably formed integrally with the arms and annular ring. The cylindrical member 43 is open at the top and bottom and receives therein a sheet-metal tube 'or guide 4.5, the tube beingrigidlyconnected to the 15 ring 43 as by soldering- Positioned within the tube 45 and resting upon a-cushioningspring46 is arhermetically sealed acid bottle 48 having a frangible end 49, the bottle being of a capacity to hold the required volume 'of chlorosulphonic 7 acid. 7

Carried by the cover 15' in alignment with the tube-45 is a pointed projection 50, which is riveted to the cover-at 51. Also carried by the cover 1'5", is acup-shaped-member 57, held in place by'th'e rivet '51. This memberhas a downwardly-extend ing tubular flange 58 which is concentric with and surrounds the upper end of the tube 45. This tubularextension is so spacedfrom the upper end of "the tube-45 that'a constricted annular passage 52 is formed therebetween through which the chemicals how when being mixed to control the rate of mixing of thechemicals and to prevent the premature discharge "from the extinguisher of acid unacted upon by the basic solution confined within the outer container 10'.

'In' referring aboveto the superior or exceptional fire-extinguishing characteristics of these various substances, we'have had more particularly in mind comparison with the present-day requirements 1 5 and conditions which have to bemet in the speci-' fied tests outlined by Underwriters Laboratories.

While the materials and compositions and method herein describedconstitute preferred -embodiments-of our invention, it is tobe understood that the invention is not limited to these precise materials, compositions or 'method, and that changes may bemade therein withoutdeparting from the scope of our invention as defined in the appended claims.

i What is claimed is:

1. A fire extinguisher containing a liquid comprising a gas-generating material and a foam stabilizer, and a second liquid comprising a chemical adapted to react with the first liquid upon use f the extinguisher to produce a stabilized foam, one of said liquids containing in addition a high concentration of a compound of an alkali metal element adapted to improve the fire-extinguishing qualities of the foam.

2. A fire extinguisher containing a liquid com-. prising a gas-generating material and a foam stabilizer, and a second liquid comprising a chemical adapted to react with the first liquid upon use of the extinguisher to produce a stabilized foam, one of said liquids containing in addition ahigh concentration of a compound of potassium adapted to improve the fire-extin uishing qualities of the foam. i

3. A fire extinguisher containing a liquid comprising a gas-generating material and a foam stabilizer, and a second liquid comprising a chemical adapted to react with the first liquid upon use of the extinguisher to produce a stabilized foam, one of said liquids containing a highconcentration of a compound comprising an alkali metal element combined with a carboxylic. acid radical, said compound having inherently exceptional fire-extinguishing properties and adapted to improve the fire-extinguishing properties of 4. A fire extinguisher containing a liquid comprising a gas-generating ma erial and a foam stabilizer, and a second liquid comprising a chemical adapted to react with the first liquid upon use of the extinguisher to produce a stabilized foam, one of said liquids containing an alkali metal lactate.

5. A fire extinguisher containing a liquid comprising a gas-generating material, .and a foam stabilizer, and a second liquid comprising a chemical adapted to reactwith the first liquid upon use of the extinguisher to produce a stabilized foam, one of said liquids containing an alkali metal acetate. 7

6. A fire-extinguishing composition for. foam extinguishers adapted to be reacted with an acid material with resultant production of a fire extinguishing foam, said composition comprisinga carbonate, a foam stabilizer, and a compound of an alkali metal element other than a carbonate in an amount by weight in excess of the weight of the carbonate and adapted to improve the fire ex tingui shing qualities of the foam. a

7. A fire-extinguishing liquid for foam extinguishers adapted to withstand low temperatures comprising agas-generating material, a foam stabilizer, and an alkali metal compound of such character and in sufficient concentration to both materially lower thefreezing point of the solution and to increase the fire-extinguishing properties of the foam.

8. A fire-extinguishing composition for foam extinguishers comprising a gas-generating material, a foam stabilizer, and an alkali metal lactate. 9. A fire-extinguishing composition for foam extinguishers comprising a gas-generatingmaterial, a foam stabilizer, and an alkali metal acetate. 10. A fire-extinguishing composition for foam extinguishers comprising a gas-generating material, a foam stabilizer, potassium lactate, and potassium acetate.

11. Afire-extinguishing composition for foam extinguisher comprising a gas-generating material, a foam stabilizer, an alkali metal-lactate, and an alkali metal acetate.

12. A fire-extinguishing liquid for foam extinmating 0 .C. and below to generate a fire-extinguishing foam.

14. A fire extinguisher containing a liquid comprisinga gas-generating material, a foam stabilizer, andga freezing temperature'depressant, said liquid being. adaptedto withstand extremely low temperatures without freezing, and an acid liquid adapted to withstand extremely low temperatures without freezing comprising a sulphonic acid, chemically active'with respect to said first mentionedliquid at temperatures approximating O C. and below to generate a fire-extinguishing foam. a

15. A fire-extinguishing composition for foam extinguishers, comprisingsodium bicarbonate, a foam stabilizer, and a high concentration of a compound of an alkali metal element of group I of the periodic table having inherently exceptional fire-extinguishing properties and adapted to improve the fire extinguishing properties of the foam. I v v 16. A fire-extinguishing composition for foam extinguishers, comprising sodium bicarbonate, a foam stabilizer, and a compound including potas sium combined with-a carboxylic acid radical.

17. A fire-extinguishing composition for foam extinguishers, comprising a carbonate which is not sufiiciently. alkaline inwaterisolution to destroy the'foam, a foamstabilizer, and a high concentration'of an alkali metal compound improving the fire-extinguishing properties of the foam and which is not suifioiently alkaline todestroy the foam.

18. 'A fire"extinguishing composition-comprising a' Watersolution containing an alkali metal lactate and an alkali metal acetate in a concentration topro'vide a freezing point of the solution below 40? C. i is 1 V 19. The method in the" extinguishing of fire, which comprises reacting a gas generating material with an acid material in the presence of both a foam stabilizer and a solution of high concentration of an alkali metal compound having inherently exceptional fire extinguishing properties to produce a wet foam carrying dispersed drops ofthe solution containing the alkali metal compound in high concentration, and discharging the wet foam onto the fire so that the dispersed drops of the'solution'containing the alkali metal compound in high concentration carried along by the foam assist and improve the normal extinguishing'action of the foam.

20. A fire-extinguishing composition for foam extinguishers comprising a gas-generating 'material, foam stabiiizer,'and an alkalimetal lactate in sufiicient concentration to materially lower the freezing point of the solution.

- CHARLES A. THOMAS.

CARROLL A. HOCHWALT. 

